Brown defeated Attorney General Doug Gansler and Del. Heather Mizeur for the nomination. Hogan — a real estate broker who served as secretary of appointments in former GOP Gov. Robert Ehrlich’s administration from 2003 to 2007 — defeated Harford County Executive David Craig, Charles County businessman Charles Lollar and Del. Ron George.

Brown’s victory puts Gov. Martin O’Malley’s partner of more than seven years up against the founder of a grassroots political organization from Anne Arundel County in November’s race for the job of Maryland’s chief executive. O’Malley is limited to two terms.

Anthony Brown Speaks After Winning Primary

With 90 percent of precincts reporting, Brown won about 51 percent of the vote in the Democratic primary. Attorney General Doug Gansler finished second with 24 percent of the vote. Del. Heather Mizeur, who ran a grassroots campaign with public financing, got 22 percent of the vote.

Gansler said he called Brown to congratulate him Tuesday night.

“We had a spirited debate on the issues,” Gansler said. “We agreed on a lot more than we disagreed.”

Mizeur, who used public campaign financing and whose campaign didn’t have nearly as much money as Brown’s or Gansler’s, said her campaign illustrated how effective a grassroots campaign can be.

“There were a lot of skeptics who said I would never make it this far,” Mizeur said. “People who lead from fear told me to get back in line. But together, we showed them the power a movement can have when we work together for positive change.”

Brown’s victory marked a major step toward his becoming Maryland’s first black governor in a state where registered Democrats outnumber Republicans by a 2-to-1 margin. Brown also would be the state’s first lieutenant governor to win the governorship. He thanked supporters for campaigning with a spirit that each person was part of something bigger.

“Each of us is part of that mission,” Brown said. “Each of us is part of that purpose. Each of us is part of that goal to build a better Maryland.”

In the Republican primary, Hogan won 43 percent of the vote, compared to Harford County Executive David Craig, who won 30 percent. Charles County businessman Charles Lollar won 15 percent, and Del. Ron George of Anne Arundel County won 12 percent.

Larry Hogan Speaks After Winning Primary

Hogan said he would continue his campaign to change Maryland with a strong focus on the economy.

“Our entire focus is on jobs, middle-class families and restoring our economy,” said Hogan, who served as appointments secretary under former Gov. Robert Ehrlich.

Meanwhile, Sen. Brian Frosh of Montgomery County rallied from behind in early polls to defeat Del. Jon Cardin, a Baltimore County delegate who had considerable statewide name recognition with the help of his uncle, U.S. Sen. Ben Cardin. Frosh was endorsed by O’Malley and many other state Democratic leaders and labor unions who helped him overcome a 6 percentage point deficit in a poll published by The Washington Post two weeks before the election. Frosh said it was a tough race.

“Oh, my God, yes,” he said in a telephone interview after winning Tuesday night, noting the flurry of endorsements late in the race helped build support to carry him to victory.

Comptroller Peter Franchot and Republican William Campbell were unchallenged in Maryland’s other statewide primary race for comptroller.

This year’s primary was unusually early for Maryland. It was moved from September to June to comply with federal rules requiring states to send ballots to members of the military and other Americans overseas. It also was marked by low voter turnout.

In Maryland’s congressional primaries, the state’s eight members of Congress cruised to easy victories after facing mostly little-known and poorly funded challenges. Rep. Steny Hoyer and Rep. John Delaney, both Democrats, were unchallenged. Republican Dan Bongino won the GOP primary to challenge Delaney in November.

A handful of state legislative primary races resulted in losses by incumbents. Republican Sen. David Brinkley, the Senate minority leader, lost to Del. Michael Hough in a western Maryland district that includes much of Frederick County and some of Carroll County. On the Eastern Shore, Republican Del. Adelaide Eckardt defeated Sen. Richard Colburn in a district that includes Talbot County, as well as parts of Dorchester, Caroline and Wicomico counties. Democratic Del. Keiffer Mitchell lost in a Baltimore district that included three incumbents running in a newly drawn district with only one seat. Del. Melvin Stukes was the other incumbent to lose. Del. Keith Haynes prevailed.

(TM and Copyright 2014 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2014 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)